The front brake discs consist of an inner carrier, which is mounted to the wheel, and an outer rotor. Both parts must be changed together as a pair.
Remove the front wheel (sect. 7 - 1, Removal of the front wheel).
Undo the retaining screws (5) of the disc to the wheel, remove the disc (7) and, on its left side, slide out the phonic wheel (6).

Removal of the front brake system
Overhauling the front brake componentsRemoving of the rear wheel
Place the motorcycle on the rear service stand and engage the 1st gear.
Remove the clip (6).
Using a suitable socket wrench, loosen the wheel nut (1).
Fully unscrew the nut (1), then remove the washer (2) and the spacer (3).
Remove the rear wheel from the motorcycle.
...
Refitting the timing belts
Rotate the pulleys on the timing belt driveshaft until the timing mark on the
outer roller is aligned with the mark on the
clutch-side crankcase cover.
In this condition, the horizontal cylinder piston will be at top dead centre.
Install in the alternator cover seat the tool code 88713.20 ...
Refitting the rear wheel eccentric hub and rear wheel shaft
Refitting is the reverse of removal, with attention to the following points.
If the calliper bracket locating pin (14) was removed, apply the recommended
threadlocker on reassembly.
Tighten the pin (14) to the torque of 33 nm +/- 5% (sect. 3 - 3, Frame torque
settings).
If previously ...